ARCHIVED REPORTS XR0001465 - Laserfiche WebLink

Home Browse Search

10 for full-scale implementation SJCEHD approved the workplan in correspondence dated August 6, 2002 The air sparging and soil venting pilot test was performed in January 2003 The pilot test results were submitted in the March 6, 2003 Remedial Action Plan The findings indicate that this approach would be effective in remediating impacted soil and groundwater SJCEHD approved the Remedial Action Plan in correspondence dated March 25, 2003 IUnder an approved San Joaquin Valley Air Pollution Control District (SJVAPCD) permit, PSC installed the soil vapor extraction (SVE) system and began continuous operation on November 18, 2003 During system operation, airflow rates are measured weekly in spargmg well ' SP-1 and in venting wells VW-1 and MW-2 The combined venting rates prior to the addition of dilution air for VW-1 and MW-2 have ranged from 2148 cubic feet per minute (cfm) to 90 05 cfm, as of December 16, 2004 In addition, three vapor samples are collected from the influent stream prior to the addition of dilution air (designated Influent), the air stream after treatment by the first carbon vessel (designated GAC-1), and from the discharge from the second and final carbon vessel (designated GAC-2) The samples are then submitted to an analytical laboratory for BTEX and TPH-g analyses Results are reported to the SJVAPCD A quarterly groundwater-monitoring event was performed in January 2004 The event data indicated that the groundwater elevation was approximately I 17 feet lower than the previous event performed in April 2003 During this event, the average depth to groundwater was 29 16 feet below ground surface (bgs) 1-19 39 feet mean sea level (msl)) All referred bgs measurements are taken from the top of well casing The groundwater flow direction was easterly at a gradient of approximately 0 005 feet per linear foot Petroleum hydrocarbons were detected in well MW-2, but concentrations were ' significantly lower than in previous events BTEX and TPH-g were not detected in the samples collected from wells MW-1, MW-3, or MW-4 Oxygenates were not detected during this event ' The April 2004 quarterly groundwater-monitoring event indicated that the groundwater elevation increased approximately 142 feet from the previous 1 event performed in January 2004 During this event, the average depth to groundwater was 27 73 feet bgs (-17 97 feet msl) The groundwater flow direction was easterly at a gradient of approximately 0 005 feet per linear foot ' Benzene was not detected in well MW-2 during this event The concentrations of toluene, ethylbenzene, xylenes, and TPH-g in well MW-2 decreased significantly from previous events BTEX and TPH-g were not ' detected in the samples collected from wells MW-1, MW-3, or MW-4 The • oxygenate MTBE was detected in well MW-2, but was not detected in the 4 Quarterly Groundwater Monrtonng Report 4th Quarter-November 2005 Prepared for SARA LEE BAKERY GROUP,INC Prepared by PSC Environmental Services Investigative and Quarterly Report 14th Quarterly Report 11_2005 doc February 24,2006